Column balancing may be defined as the technique of dividing an entity to be displayed into a number of columns of substantially similar size. The most common example of column balancing may be found in newspapers, magazines and books, wherein pages are often presented in columns of text in which the number of text lines within columns are of approximately equal length.
This invention is related to the controlling of the column balancing function as opposed to an algorithm for the act of column balancing itself. For examples of algorithms related to the act of column balancing itself, reference is made to U.S. Pat. Nos. 4,575,813, issued Mar. 11, 1986 and 4,608,664, issued Aug. 26, 1986, both filed Feb. 23, 1983 by G. M. Bartlett et al, both entitled "Automatically Balancing and Vertically Justifying a Plurality of Text/Graphics Columns", and both assigned to the assignee of this invention.
Current editing and formatting systems limit column balancing of text data to single pages and to all text data on a given page. This occurs, in part, because the page layout function of current document composition systems does not possess the notion of a layout capability that is separate from the data. Existing formatting products require that the columns which are to contain the balanced data be physically adjacent and that "controls" within the text data indicate a single or multiple column format mode. There is no notion of "formatting models" which can be separately specified from the data itself with an indication of which columns are or are not identified as members of a particular "column balance set".
By way of example, one practical application of column balance sets is keep unbalanced footnote data under the balanced columns in which the footnote reference occurred.
The greater the amount of data that participates in a column balance function, the more pleasing the visual effect of a "balanced column set". In current editing products, when the data to be balanced is unequal on successive pages, the reader's perception is that some pages are "well balanced" while others are not. This effect is especially noticeable for "facing" pages of an open book. It would, therefore, be highly advantageous to achieve column balancing across page boundaries and column balancing of a portion of, rather than all of, the text on a single page.